package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import cn.hutool.core.util.BooleanUtil;
import cn.hutool.core.util.StrUtil;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Blog;
import com.hmdp.entity.User;
import com.hmdp.mapper.BlogMapper;
import com.hmdp.service.IBlogService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IUserService;
import com.hmdp.utils.RedisConstants;
import com.hmdp.utils.SystemConstants;
import com.hmdp.utils.UserHolder;
import lombok.RequiredArgsConstructor;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
@RequiredArgsConstructor
public class BlogServiceImpl extends ServiceImpl<BlogMapper, Blog> implements IBlogService {


    private final IUserService userService;
    private final StringRedisTemplate stringRedisTemplate;

    @Override
    public Result queryBlogById(Long id) {
        //查询blog
        Blog blog = getById(id);
        if(blog == null){
            return Result.fail("笔记不存在");
        }
        //查询blog相关的用户对象
        queryBlogUser(blog);
        //3. 查询blog是否被点赞了
        isBlogLiked(blog);
        return Result.ok(blog);
    }

    private void isBlogLiked(Blog blog) {
        UserDTO user = UserHolder.getUser();
        if(user == null ){
            return ;
        }
        //1 获取当前登录用户
        Long userId = user.getId();
        //2 判断当前登录用户是否点赞
        String key = RedisConstants.BLOG_LIKED_KEY + blog.getId();
        Double score =  stringRedisTemplate.opsForZSet().score(key,userId.toString());
        blog.setIsLike(score != null);

    }

    private void queryBlogUser(Blog blog) {
        Long userId = blog.getUserId();
        User user = userService.getById(userId);
        blog.setName(user.getNickName());
        blog.setIcon(user.getIcon());

    }

    @Override
    public Result queryHotBlog(Integer current) {
        // 根据用户查询
        Page<Blog> page = query()
                .orderByDesc("liked")
                .page(new Page<>(current, SystemConstants.MAX_PAGE_SIZE));
        // 获取当前页数据
        List<Blog> records = page.getRecords();
        // 查询用户
        records.forEach(blog -> {
            this.queryBlogUser(blog);
            this.isBlogLiked(blog);
        });
        return Result.ok(records);
    }

    @Override
    public Result likeBlog(Long id) {
        //1 获取当前登录用户
        Long userId = UserHolder.getUser().getId();
        //2 判断当前登录用户是否点赞
        String key = RedisConstants.BLOG_LIKED_KEY + id;
        Double score = stringRedisTemplate.opsForZSet().score(key, userId.toString());
        if(score == null){
            //3 未点赞  可以点赞
            boolean isSuccess = update().setSql("liked = liked + 1").eq("id", id).update();
            //3.1 数据库点赞数加1  并把用户添加到redis中的set集合中  zadd  key  value  score
            if(isSuccess){
                stringRedisTemplate.opsForZSet().add(key,userId.toString(),System.currentTimeMillis());
            }

        }else{
            //4 如果已点赞  取消点赞
            boolean isSuccess = update().setSql("liked = liked - 1").eq("id", id).update();
            //3.1 数据库点赞数减1   并把用户从redis的set集合中去掉
            if(isSuccess){
                stringRedisTemplate.opsForZSet().remove(key,userId.toString());
            }
        }
        return null;
    }

    //点赞列表top5用户
    @Override
    public Result queryBlogLikes(Long id) {
        String key = RedisConstants.BLOG_LIKED_KEY + id;
        //1 查询点赞用户top5  zrange key 0 4
        Set<String> top5Id = stringRedisTemplate.opsForZSet().range(key, 0, 4);
        if(top5Id == null || top5Id.isEmpty()){
            return Result.ok(Collections.emptyList());
        }
        //2 解析出其中的用户id
        List<Long> userIdList = top5Id.stream().map(Long::valueOf).collect(Collectors.toList());
        String idStr = StrUtil.join(",", userIdList);
        //3 根据用户id查询用户
        List<UserDTO> userDTOs = userService.query().in("id",userIdList).last("order by field (id," + idStr + ")").list()
                .stream()
                .map(user -> BeanUtil.copyProperties(user, UserDTO.class))
                .collect(Collectors.toList());
        //4 返回
        return Result.ok(userDTOs);
    }
}
